1. Technical Field
The present invention relates to an organic EL device and an electronic apparatus.
2. Related Art
As a luminescence element using a phenomenon of light emission occurring thanks to the electron-hole recombination, an organic luminescence element (hereinafter, referred to as an organic EL element) is known. The organic EL element includes an organic functional layer having an organic light emission layer formed of an organic EL material between anodes supplying electron holes and cathodes supplying electrons, and emits light when the supplied electron holes and the supplied electrons are recombined.
As a device including the organic EL element, there is an organic electroluminescence device (hereinafter, referred to as an organic EL device) (for example, JR-A-2002-132186 and JP-A-2003-76301). The organic EL device includes a TFT substrate in which TFTs are arranged in a matrix shape, for example, and an interlayer insulation film which covers the TFTs. Openings are formed through the interlayer insulation film on drains of the TFTS, and source electrodes electrically connected to the drains of the TFTs are formed inside the openings. A ground layer such as a protective film or a flatness layer covering the source electrodes and the interlayer insulation film is provided. In the ground layer, openings are formed on the source electrodes. A conductive film electrically connected to each of the source electrodes is provided inside each of the openings. The conductive film is drawn up to a predetermined location (pixel opening) on the flatness layer and configured as a pixel electrode in the pixel opening. The pixel electrode functions as an electrode (anode) of the organic EL element. The organic functional layer and a cathode are formed above the pixel electrode.
This organic EL device is broadly classified into a bottom emission type organic EL device obtaining light from the anode and a top emission type organic EL device obtaining light from the cathode. The top emission type organic EL device includes a reflective film which reflects the light emitted from the anode toward the cathode. Specifically, the reflective film (for example, an aluminum film) is formed at the locations corresponding to the pixel openings on the flatness layer. In addition, the conductive film electrically connected to the source electrode is drawn up to the reflective film.
In the top emission type organic EL device capable of realizing a full color display, a configuration in which the cathode is configured as a transflective film and the anode and the reflective film form a resonator may be taken into consideration (for example, JP-A-2007-26849). Specifically, a minimum unit for realizing the full color display is formed by a plurality of monochromatic display members (for example, red, green, and blue members). One monochromatic display corresponds to one organic EL element. For example, the thickness of the pixel electrode can be varied by forming a film with a material for forming the conductive film three times in a portion corresponding to the red member, two times in a portion corresponding to the green member, and once in a portion corresponding to the blue member. With such a configuration, it is possible to adjust an optical distance between the cathodes and the reflective film, that is, a resonant wavelength. Accordingly, light having wavelengths corresponding to respective colors can be emitted from the anodes, thereby obtaining a satisfactory display.
However, when the pixel electrodes formed by the conductive films having a plurality of layers are used, a problem may occur in that a cut portion occurs in the periphery of the pixel electrode. In particular, the cut portion occurs in the thinnest pixel electrode (for example, the blue member). That is, the reflective film is provided below portions in which the pixel electrodes are formed. In addition, a stepped portion is formed on the reflective film and the periphery of the reflective film. When the material for forming the pixel electrodes is cut in the stepped portion, the cut portion is filled with the material in the pixel electrodes corresponding to the green and red members upon forming the film two times. However, the cut portion just remains in the pixel electrode corresponding to the blue member without repair, since the film is formed just once. When the cut portion occurs in the pixel electrodes, the organic EL elements corresponding to the pixel electrodes may not emit light and become black points. Accordingly, a display failure arises. When only one monochromatic display member (for example, the blue member) becomes the black point, a desired full color display may not be obtained, thereby degrading a display quality.